FracSYS Prototype is the first demonstrator of FracSYS's functionalities. It applies these features to the case study of the Cleuson-Dixence gallery in Valais, Switzerland, modelling the faults that intersect the gallery and water inflow. More information on the methodology is available on the FracSYS homepage. The conceptual geological model of Cleuson-Dixence is available on Visual KarSYS. The FracSYS prototype was developed in collaboration with SISKA, CREALP and i4DS.